If you want to run one of those you would be better off getting a marine weiand 177 set up, parts much easier to come up with, merc specialized some parts and now some imposssible to find....I ran one on a 489 worked awsome...Rob

ya i bought it off ebay it took 3 weeks to get but im satisfied now, i was worried for awhile seller wouldnt return any emails then 1 day it showed up

Sorry Stingray for the incorrect info. To my knowledge - After thinking about it with 7.5 pds of boost it would in effect only bump your compression to near 9.5/1. It's been several years but I did look back and realized that I had used the 731 cam with the 177's on one set up and it worked fine. It wasn't long after that set up I went to 420 mega blowers and different cams 741's. (FUN) Those made just over 660 HP on the dyno. I still like the 177's though. Like Griff mentioned you may be just a tad small for a 496 CI however set up properly you'll have a good reliable package and make some noticable power also. Regardless of what you do though I would consider boost retard. You never know what kind of fuel you might get stuck with. Just a little insurance depending on what you do with pullies. You kind of got me thinking now. I still have the 525 SC blowers with very low hours. I might have to strap those on my 496's next year. HMMM.

Good luck and have fun.

That would be a good thing. It will give you a lot more pulley options. With your 8.5 static comp ratio, you should easily be able to run 5# of boost. That will give you an effective compression ratio of about 11.5:1 under full boost and you will be able to run 92-93 ocatne fuel.

Here is a good tech pdf from Holley's website. http://www.holley.com/data/TechServi...ech%20Info.pdf

"Regardless of what you do though I would consider boost retard"
Not sure what this means , is that part of a msd setup or just set the timing back? Because before i even put the blower on im going to put a msd on i have been fighting a top end miss all last season when i get to last 200 rpms it sounds like im hitting rev limiter i chaged props back to 23 then i revved higher and the last 2-300 rpms same thing i think i have it narrowed down to ignition , as i have a stock thunerbolt on a high performance engine , figure a marine msd can't hurt anything,

MSD offer a nice one that is easily controllable either at the dash or in the engine compartment.

Boost retard = retards (pulls out) ign. timing as boost goes up. If you try to run higher amounts of boost with same total timing #'s you will have detonation and that can lead to pistion, rings, bearing failure. So your options are to set timimg lower and live with less preformance under low boost cond. Set timing norm and limit boost so you don't get detonation. Or install a boost retard, so you can run your norm timing settings and as the retard box see's a pressure on it, it pulls timing out.

Most are adjustable for boost and degrees of timing. So you can set it for say.. For every 1 psi boost, it retards timing by X amount of degrees

GOOD INFO>

I really don't see any reason for a boost retard system in a low boost application. Just set total timing to about 30*. You could probably just run the timing locked at 30* or maybe set up the distributor with 10-15* of advance all in by 3500rpms and then set base timing at 15-20*.

could not retarding the timing cause head gasket failure?

I started cleaning and inspecting all my sc components lately and everything looks good but the intake it has been in salt water and its very corroded t stat is all ate out of intake and coolant jackets entering intake have been dev coned and someone did a terrible job doing it then there is a blower stud snapped off flush tried drilling it, it will not drill cant tell if its stainless or if someone broke a bit off in it anyways , I guess i either need a used intake or can you still buy these from b and m or weind , not sure what to do but id like to get things organized before long it will be time to start working on it , any help would be appreciated